{"attribution":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","cve":{"id":"CVE-2026-40394","sourceIdentifier":"cve@mitre.org","published":"2026-04-12T20:16:17.857","lastModified":"2026-10-26T21:10:00.170","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"Varnish Cache 9 before 9.0.1 and Varnish Enterprise before 6.0.16r11 allows a \"workspace overflow\" denial of service (daemon panic) for certain amounts of prefetched data. The setup of an HTTP/2 session starts with a speculative HTTP/1 transport, and upon upgrading to h2 the HTTP/1 request is repurposed as stream zero. During the upgrade, a buffer allocation is made to reserve space to send frames to the client. This allocation would split the original workspace, and depending on the amount of prefetched data, the next fetch could perform a pipelining operation that would run out of workspace."},{"lang":"es","value":"Varnish Cache 9 anterior a la versión 9.0.1 y Varnish Enterprise anterior a la versión 6.0.16r11 permiten una denegación de servicio por ’desbordamiento de espacio de trabajo’ (pánico del demonio) para ciertas cantidades de datos precargados. La configuración de una sesión HTTP/2 comienza con un transporte HTTP/1 especulativo, y al actualizar a h2, la solicitud HTTP/1 se reutiliza como flujo cero. Durante la actualización, se realiza una asignación de búfer para reservar espacio para enviar tramas al cliente. Esta asignación dividiría el espacio de trabajo original y, dependiendo de la cantidad de datos precargados, la siguiente recuperación podría realizar una operación de pipelining que agotaría el espacio de trabajo."}],"affected":[{"source":"cve@mitre.org","affectedData":[{"vendor":"varnish-software","product":"Varnish Cache","defaultStatus":"unaffected","versions":[{"version":"9.0.0","lessThan":"9.0.1","versionType":"semver","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"cve@mitre.org","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L","baseScore":4.0,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW"},"exploitabilityScore":2.2,"impactScore":1.4},{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-04-13T15:45:49.035659Z","id":"CVE-2026-40394","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"cve@mitre.org","type":"Secondary","description":[{"lang":"en","value":"CWE-670"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:varnish-software:varnish_enterprise:*:*:*:*:*:*:*:*","versionEndIncluding":"6.0.15","matchCriteriaId":"E53A64C0-FC22-40B5-8C3B-6288B44AC3FC"},{"vulnerable":true,"criteria":"cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r1:*:*:*:*:*:*","matchCriteriaId":"F24D68B5-362E-4797-B6DE-C19A2893186C"},{"vulnerable":true,"criteria":"cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r10:*:*:*:*:*:*","matchCriteriaId":"910BAD01-26E5-4D12-AA23-0BD2D48F229C"},{"vulnerable":true,"criteria":"cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r2:*:*:*:*:*:*","matchCriteriaId":"05E529DF-DEE1-4A62-998B-CA312DF888FD"},{"vulnerable":true,"criteria":"cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r3:*:*:*:*:*:*","matchCriteriaId":"8AB27B34-2951-4755-851C-7C942DAFB6C7"},{"vulnerable":true,"criteria":"cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r4:*:*:*:*:*:*","matchCriteriaId":"18A22D42-B038-4E09-92DD-8AFD2F51A340"},{"vulnerable":true,"criteria":"cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r5:*:*:*:*:*:*","matchCriteriaId":"FE76D616-3AA8-4D9A-9D41-9AE35FE20DBC"},{"vulnerable":true,"criteria":"cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r6:*:*:*:*:*:*","matchCriteriaId":"9C5610CF-1FE4-4DF8-8D49-7C0CCF0359E4"},{"vulnerable":true,"criteria":"cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r7:*:*:*:*:*:*","matchCriteriaId":"27B776B2-9C38-45BE-89E4-ECDEEAE538A9"},{"vulnerable":true,"criteria":"cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r8:*:*:*:*:*:*","matchCriteriaId":"ED3CA600-C88D-4825-8C36-E052822AF59F"},{"vulnerable":true,"criteria":"cpe:2.3:a:varnish-software:varnish_enterprise:6.0.16:r9:*:*:*:*:*:*","matchCriteriaId":"6B1D57B1-9771-4195-9EE3-B26EA776FB6B"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:vinyl-cache:vinyl_cache:9.0.0:*:*:*:*:*:*:*","matchCriteriaId":"9868204A-88AD-46D2-BE0B-92FF686B7DE4"}]}]}],"references":[{"url":"https://docs.varnish-software.com/security/VEV00002/","source":"cve@mitre.org","tags":["Vendor Advisory"]}]}}